Epilepsy is less likely a cause of your sleep disorder because in cases of epilepsy, a person can't remember any details during sleep. More serious psychiatric disorders(psychoses for example) are also not likely causes of these symptoms because people with psychoses consider themselves normal and don’t ask for medical help on their own. According to your description, you might be experiencing some nightmares, such as a “frozen state”, but you don’t remember them. Stress and anxiety could be the possible cause for your sleeping disorder.
You may ask for help from a mental health doctor.